1. Field of the Invention
The present invention relates to a track jump control circuit used in an optical record and playback apparatus or the like.
2. Description of the Related Art
Generally, in an optical record and playback apparatus such as a compact disc player (CD player), or compact disc ROM (CD-ROM), information stored on a disc is read by a pick-up.
In such an optical record and playback apparatus, when reading information by means of the pick-up, the pick-up is moved at a low speed so as to follow tracks. When placing the pick-up to a desired position, the pick-up is moved at a high speed so as to jump tracks.
A track jump control circuit for conducting such a track jump operation is disclosed in Japanese Patent Application Serial No. SHO 60-117203.
With the track jump control circuit, in the track jump state, the moving speed of the pick-up is detected. The completion of the track jump operation is determined by the moving speed.
However, with the aforementioned track jump control circuit, if a vibration is applied to the optical record and playback apparatus, the vibration component is added to the speed signal of the pick-up. Thus, the completion of the track jump cannot be precisely determined.
In addition, the speed signal of the pick-up is obtained only after the pick-up is moved. Thus, the response of the early stage of the track jump is slow.